Stage cementing collar



2 Sheets-Sheet 1 3 5 H Z M v J 4 M w Y J a. M v wfi \Ni J 7. a a My 2 .w h & Z 1 65 F Aug. 29, 1967 M. B. CONRAD STAGE CEMENTING COLLAR Filed Dec. 14, 1964 Aug. 29, W67 M. B. CONRAD STAGE CEMENTING COLLAR 2 SheetsSheet 2 Filed Dec. 14, 1964 INVENTOR, MAZW/l/ 453 (WA/E40 United States Patent 3,338,311 STAGE CEMENTING COLLAR Martin B. Conrad, Downey, Calif. (R0. Box 568, Carpinteria, Calif. 93013) Filed Dec. 14, 1964, Ser. No. 418,135 11 Claims. (Cl. 166-154) ABSTRACT OF THE DISCLOSURE A cementing collar including a ported sleeve received in a tubular member and held in a first position with the sleeve ports spaced from ports in the tubular member by means of an inner body releasably connected to the sleeve, with the sleeve being movable to a second position with the inner member, and thence to a third position to again space the ports by being shifted relative to both the tubular member and the inner member.

The present invention relates to a multiple stage cementing collar, and more particularly to a device adapted to be installed in a string of well casing and having one or more ports therein controlled by a sleeve movable longitudinally of the casing so that it is possible to effectively place more than one stage of cement on the outside of the string of casing at different elevations within the well. Such collars are useful in well cementing operations to enable the cementing of the casing string to its full extent.

It is the practice in the cementing of well casing within bore holes in the earth to displace by means of surface pumps a pumpable cement slurry down through the casing to the bottom of the casing string and thence upwardly through the annulus to the surface, the return of cement to the surface in the annulus being indicative of the annulus having been filled with the cement slurry. Oftentimes, it is desirable or necessary in order to assure complete filling of the annulus and in order to reduce the so-called channeling of the cement or to facilitate the displacement of the cement with low pump pressure at the surface, that ports in the casing above the lower extremity of the casing be opened to allow cement to be displaced laterally through the casing openings, and thence to return to the surface from an intermediate elevation at which the ports are located. Various stage collar devices have heretofore been employed whereby the ports may be opened, and then closed, following displacement of the cement through the ports, such devices in general being rather complex or dependent upon the action of cement slurry or fluid pressure responsive faces provided upon the movable components.

The present invention contemplates as a principal objective the provision of a simple stage collar device which may be characterized as a single sleeve stage collar device in the sense that but one sleeve or movable member having radial ports therein is employed to close the ports in the collar when in one position, when in a second position to open the ports, and when in a third position to again close the ports.

A further object of the invention is to provide a stage collar of the aforementioned character which is easily operable by a first stage tripping device which may be characterized as a bomb so as to move the collar from the first position to the second position to allow the displacement of the second stage cement and which may be easily operated by a closing plug which constitutes a topplug for the second stage of the cement.

Other objects and advantages of the invention will be hereinafter described or will become apparent to those skilled in the art, and the novel features of the invention will be defined in the appended claims.

In the accompanying drawings:

FIG. 1 is a longitudinal sectional view illustrating a fragmentary section of well casing with a multiple stage collar made in accordance with the invention incorporated in the casing string and with the single sleeve thereof in the first position at which the collar ports are closed;

FIG. 2 is a view corresponding to FIG. 1 but illustrating the single sleeve device engaged by a tripping device or bomb and in the second position at which the collar ports are open;

FIG. 3 is a view corresponding to FIGS. 1 and 2 but illustrating the single sleeve device engaged by a top cement plug and moved to the third position at which the collar ports are reclosed;

FIG. 4 is a fragmentary sectional view as taken on the line 44 of FIG. 2; and

FIG. 5 is a fragmentary sectional view as taken on the line 5-5 of FIG. 3.

Like reference characters in the several views of the drawings and the following description designate corresponding parts.

Referring to FIG. 1, the stage cementing collar device is generally denoted at S and includes an elongated tubular body 1 threaded at its upper extremity as at 2 and having at its lower extremity a coupling member 3 connected thereto and provided threads 4. The body is interposed in a string of easing generally denoted at C, the upper section of the casing string being connected to the body 1 by the threads 2 and the lower section of the casing string being connected to the body 1 by the threads 4.

Intermediate the ends of the body 1 is a suitable number of radial ports or openings 5. In accordance with the present invention it is desired that the ports 5 be closed until such time as a first stage cementing operation has been completed which would typically involve the displacement of a pumpable cement slurry downwardly through the casing string C, through the body 1, and thence upwardly about the outside of the casing string within the annulus defined between the casing and the well bore. When the first stage cementing has been completed, it is desired to open the ports 5 so that cement may be displaced laterally through the ports 5 into the above noted annulus, thus significantly reducing the distance travelled by the cement and'thereby facilitating cement displacement with consequent reduction in the necessary pump pressure at the top of the well required to cause circulation of the cement and in addition reducing the tendency of the cement to channel or have voids therein.

The body 1 provides an internal bore 6 in which is slidably disposed a tubular sleeve 7 which constitutes means for closing and opening the ports 5 as just mentioned. This sleeve 7 is accordingly provided with a number of ports 8 therein adapted to register with the ports 5 in the body 1 when the sleeve is in one relative longitudinal position within the body 1. Referring to FIG. 1, it will be noted that means are provided for initially holding the sleeve 7 in a position in which the ports 8 are spaced longitudinally from the ports 5.

Such holding means comprises a tubular inner body 9 having a passage 10 therethrough and having a conical seat 11 at the upper end of the passage. The sleeve 7 is secured to the body 9, with the latter projecting from the lower end of the sleeve, as by means for a suitable number of frangible elements which, in the illustrative embodiment, are comprised by shear screws 12 adapted to hold the sleeve in an initial relationship to the body 9 such that the ports 8 in the sleeve are axially displaced from the ports 5.

Cooperative with the body 9 for so holding the sleeve 7 is a ring 13 secured in position by the coupling 3 in a seat-14 within the outer body 1. Frangible means or elements in the form of shear screws 15 interconnect the lower extremity of the body 9 to the ring 13 so that the body 9 and the sleeve 7 are rigidly interconnected to place within the bore of the outer body 1. For a purpose which will hereinafter more fully appear, the body 9 is also provided with an external shoulder 16 projecting outwardly for abutting engagement with the ring 13 follow ing shearing of the shear screws 15.

Suitable seal means in the form of a pair of seal rings 17 and 18 are interposed at the interface between the sleeve 7 and the inner body 9, and a pair of sealing rings 19 .and 20 are preferably interposed between the sleeve 7 and the bore of the body 1.

Inasmuch as during operation of the stage collar the body 9 must move downwardly relative to the stop ring 13 to enable abutment of the shoulder 16 against the stop ring, the latter is provided with a fluid passage 21 so that fluid may not be trapped and interfere with downward movement of the body 9. Similarly, a fluid passage 22 extends into the region between the seal rings 17 and 18 through the stop shoulder 16 and through the body 9 into an annular space 23 lying between the seal rings 17 and 18 in the body 9.

At the upper extremity of the sleeve 7 it is provided with actuator means in the form of a collar or ring 25 which is suitably connected to the sleeve 7 by fasteners 25 or which is otherwise formed as a part of the sleeve 7 this ring 25 being sealingly and slidably engaged within ring 25 presents an upwardly facing conical seat 27 which the bore of the body 1 and having a seal ring 26. The is of a diameter larger than the diameter of the conical seat 11 of the body 9 and the ring 25 also has an opening 28 therethrough which is correspondingly larger than the opening 10 through the body 9.

It will now be observed that the stage collar device when made up in the casing string would be in the condition as shown in FIG. 1 with the shoulder 16 of body 9 spaced axially upwardly above the stop ring 13 and with the sleeve 7 held in a position with the ports 8 therein spaced upwardly above the ports 5 in the body 1.

During use of the device as shown in FIG. 2, a tripping device or bomb B may be employed to pass downwardly through the body of fluent cement slurry within the casing C following the displacement of the first stage of cement. The bomb B is preferably provided with a conical nose 30 having an upwardly extended central stem 31 about which is disposed a body of weighted material 32, whereby the bomb B will rapidly gravitate through a body of fluent cement within the casing C. Inasmuch as the opening 28 in the conical seat 27 of ring 25 is larger in diameter than the seat 11, it will be understood that the conical nose 30 of the bomb B will facilitate the passage of the bomb through the opening 28 into engagement with the conical seat 11 of the lower body 9.

The conical head 30 of the bomb sealingly engages with the conical seat 11 so that the application of pressure to the column of fluid above the bomb when seated on the body 9 will impose the pressure across the entire area of the body 9 within the sleeve 7 to exert a downward force on the shear screws 15 which will ultimately part and allow downward movement of the body into engagement with the stop ring 13 as viewed in FIG. 2. At this time the ports 5 in the body and the ports 8 in the sleeve 7 are in registry as shown in FIG. 2 so that fluid will pass laterally therethrough. Accordingly, the second stage of cement may be pumped through these ports into the annulus outside of the body 1 within the wall bore.

Referring now to FIG. 3, there is illustrated a closing device or tap plug which is adapted to engage the upper ring 25 on the sleeve 7 to effect downward movement of the sleeve to the position shown in FIG. 3 whereat the ports 8 in the sleeve have moved downwardly beyond the ports 5 in the body 1, thereby closing oif the latter. The

top plug or closing device is generally denoted at P and includes an inner body 34 which at its lower extremity has a conical end 35 adapted to seat'upon the conical seat 27 of the ring 25. Internally of the top plug 34 is an opening which has an upwardly tapering section 36 to accommodate the upper end of the bottom plug or bomb B, there being a chamber 37 above the opening 36 to accommodate the extremity of the bomb. About its outer periphery the body 34 of the top plug or closing device is provided with a suitable number of rubber ribs or wipers 38 which extend outwardly into engagement with the inner wall of the casing C so that the plug P will move downwardly through the casing C along with the cement as it is being displaced through the open ports shown in FIG. 2.

Longitudinally extending grooves 39 in the inner surface of the sleeve 7 provide communication with the space beneath the seal 17, and through ports 22 and 21; with the bottom portion of the casing C beneath the staging collar. This is needed so that liquid will not be trapped between the top plug P and the upper end of the inner body 9 upon the downward movement of the top plug P. In the absence of the communication with the lower part of the casing afforded by the passages 39, 22, and 21, liquid between the top plug P and the inner body 9 could prevent downward movement of the plug P, locking that member above the position of FIG. 3 so that the ports 5 could not be closed.

Upon contact of the top plug P with the seat 27 of ring 25, the pressure of the cement derived from the surface pumps will cause the sleeve 7 to be moved downwardly from the position shown in FIG. 2 shearing the shear screws 12 so that the sleeve 7 will be allowed to move downwardly to the position shown at FIG. 3 until it abuts with the stop ring 13.

Means are preferably provided for latching the sleeve 7 in the downwardly displaced position shown in FIG. 3 and accordingly in the illustrative embodiment the body 1 of the assembly is provided with an internal annular groove 1a which is spaced between the body ports 5 and the upper end of the sleeve 7 when the assembly is in the condition shown in FIG. 1. Between the upper extremity of the sleeve 7 and the ring 25 there is provided an annular chamber 25a in which is disposed an expansi'ble spring ring 7a which, as seen in FIGS. 4 and 5, is of sinusoidal form. Upon downward movement of the sleeve to the position shown in FIG. 3, it will be noted that the spring 7a is in registry with the body groove 1a and will snap into the latter, thereby latching the sleeve in the closed position.

While the specific details of the invention have been herein shown and described, changes and alterations may be resorted to without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. A multiple stage cementing collar, comprising: a tubular body having a lateral =port between its ends, means at the ends of said body for connecting the same in a pipe string, a sleeve slidably disposed in said body and having a lateral port registrable with said body port in one longitudinal position of said sleeve in said body, an inner body slidable in said tubular body, releasable means connecting said inner body to said tubular body, means releasably connecting said sleeve to said inner body in a position spaced from said one longitudinal position, and means in said tubular body and on said inner body for limiting sliding movement of said inner body to a position at which said sleeve is in said one position.

2. A multiple stage cementing collar, comprising: a tubular body having a lateral port between its ends, means at the ends of said body for connecting the same in a pipe string, a sleeve slid-ably disposed in said body and having a lateral port registrable with said body port in one longitudinal position of said sleeve in said body, an inner body slidable in said tubular body, releasable means connecting said inner body to said tubular body, means releasably connecting said sleeve to said inner body in a position spaced from said one longitudinal position, means in said tubular body and on said inner body for limiting sliding movement of said inner body to a position at which said sleeve is in said one position, and means engageable with said sleeve to limit movement of said sleeve to another position spaced from said one position.

3. A multiple stage cementing collar, comprising: a tubular body having a lateral port between its ends, means at the ends of said body for connecting the same in a pipe string, a sleeve slidably disposed in said body and having a lateral port registrable with said body port in one longitudinal position of said sleeve in said body, an inner body slidable in said tubular body, releasable means connecting said inner body to said tubular body, means releasably connecting said sleeve to said inner body in a position spaced from said one longitudinal position, means in said tubular body and on said inner body for limiting sliding movement of said inner body to a position at which said sleeve is in said one position, means engageable with said sleeve to limit movement of said sleeve to another position spaced from said one position, and means for latching said sleeve in said another position.

'4. A multiple stage cementing collar, comprising: a tubular body having a lateral port between its ends, means at the ends of said body for connecting the same in a pipe string, a sleeve slidably disposed in said body and having a lateral port .registrable with said body port in one longitudinal position of said sleeve in said body, an inner body slidable in said tubular body, releasable means connecting said inner body to said tubular body, means releasably connecting said sleeve to said inner body in a position spaced from said one longitudinal position, said sleeve having a seat thereon defining a central opening and said inner body having a seat thereon below said body seat and defining an opening smaller than the opening through said body seat for engagement by first and second tripping devices to respectively etfect movement of said inner body to a position in said tubular body at which said sleeve is in said one position and movement of said sleeve past said one position, means for limiting movement of said inner body to said position in said tubular body, and means for limiting movement of said sleeve past said one position.

5. A multiple stage collar as defined in claim 4, wherein said means for limiting movement of said inner body includes a stop carried by said tubular body and projecting into the path of a portion of said inner body.

6. A multiple stage collar as defined in claim 4, wherein said means for limiting movement of said inner body includes a stop carried by said tubular body and projecting into the path of a portion of said inner body, and said releasable means connecting said tubular and said inner body comprising frangible means carried by said stop and engaged with said inner body.

7. A multiple stage cementing collar, comprising: a tubular body having a lateral port between its ends and means at its ends for connection in a string of well pipe, a stop in said tubular body below said body port, an inner body slidable in said tubular body and having a stop portion opposed to said stop in said tubular body, releasable means holding said inner body with said stop portion spaced upwardly from said stop, a sleeve slidable in said tubular body and relative to said inner body, said sleeve having a port, releasable means connecting said sleeve to said inner body with said sleeve port spaced above said tubular body port a distance equal to the distance between said stop and said stop portion, said inner body having means defining a seat for engagement by a first tripping device moving through said tubular body to release said inner body, whereby said stop portion will move into engagement with said stop to position said sleeve port in registry with said tubular body port, and said sleeve having means defining a seat for a second tripping device moving through said tubular body to release said sleeve, whereby said sleeve will move downwardly to move said sleeve port below said tubular body port.

8. A multiple stage collar as defined in claim 7, wherein said sleeve and said tubular body have means for latching 'said sleeve in said downward position.

9. A multiple stage collar as defined in claim 7, wherein said inner body is disposed within the lower end of said sleeve, said inner body and said tubular body defining a space for said lower end of said sleeve, and said stop in said tubular body is disposed in the path of said lower end of said sleeve for engagement by the latter to limit downward movement of said sleeve.

10. A multiple stage cementing collar comprising: a tubular body member adapted to be mounted in a casing string to be run into a well bore, a lateral port in said body, a sleeve slidably disposed in said body and having a lateral port registrable with said body port, an additional member in said body member, releasable means cooperative with said sleeve, said body and said additional member for releasably holding said sleeve in a first position with said sleeve port spaced from said body port, means on said sleeve for moving said sleeve relative to said body member to a second position with said sleeve port in registry with said body port, releasable means for holding said sleeve in said second position, and means on said sleeve for moving said sleeve relative to said body member and to said additional member to a third position with said sleeve port spaced from said body port. I

11. A multiple stage cementing collar comprising a tubular body member adapted to be mounted in a casing string to be run into a well bore, a lateral port in said tubular body member, a sleeve slidably disposed in said tubular body member and having a lateral port registrable with said body port, an inner body member in said tubular body member and slidable relative thereto, a first releasable means connecting said tubular body member to said inner body member for normally preventing said sliding movement of said inner body member relative to said tubular body member, and a second releasable means connecting said sleeve to said inner body member, said sleeve being normally positioned by said inner body member in a first position in which said sleeve port is remote from said body port, said sleeve being movable with said inner body member upon release of said first releasable means to a second position in which said ports are in registry, said sleeve being movable relative to said inner body member upon release of said second releasable means to a third position in which said sleeve port is remote from said body port.

References Cited UNITED STATES PATENTS 1,906,891 5/1933 White 166-154 ,609 4/1939 McClendon et a1. 166-154 2,659,438 11/1953 Schnitter 166154 2,762,440 9/1956 Reed 166154 3,151,681 10/1964 Cochran 166224 CHARLES E. OCONNELL, Primary Examiner. R. E. FAVREAU, Assistant Examiner 

10. A MULTIPLE STAGE CEMENTING COLLAR COMPRISING: A TUBULAR BODY MEMBER ADAPTED TO BE MOUNTED IN A CASING STRING TO BE RUN INTO A WELL BORE, A LATERAL PORT IN SAID BODY, A SLEEVE SLIDABLY DISPOSED IN SAID BODY AND HAVING A LATERAL PORT REGISTRABLE WITH SAID BODY PORT, AND ADDITIONAL MEMBER IN SAID BODY MEMBER, RELEASABLE MEANS COOPERATIVE WITH SAID SLEEVE, SAID BODY AND SAID ADDITIONAL MEMBER FOR RELEASABLY HOLDING SAID SLEEVE IN A FIRST POSITION WITH SAID SLEEVE PORT SPACED FROM SAID BODY PORT, MEANS ON SAID SLEEVE FOR MOVING SAID SLEEVE RELATIVE TO SAID BODY MEMBER TO A SECOND POSITION WITH SAID SLEEVE PORT IN A REGISTRY WITH SAID BODY PORT, RELEASABLE MEANS FOR HOLDING SAID SLEEVE IN SAID SECOND POSITION, AND MEANS ON SAID SLEEVE FOR MOVING SAID SLEEVE RELATIVE TO SAID BODY MEMBER AND TO SAID ADDITIONAL MEMBER TO A THIRD POSITION WITH SAID SLEEVE PORT SPACED FROM SAID BODY PORT. 